#include"Date.h"
int Date::operator-(const Date& d)
{
	int flag = 1;
	Date Max = *this;
	Date Min = d;
	if (*this < d)
	{
		Max = d;
		Min = *this;
		flag = -1;
	}
	int count = 0;
	while (Max != Min)
	{
		count++;
		Min++;
	}
	return flag * count;
}
bool Date::operator != (const Date& d)
{
	return !(*this == d);
}
bool Date::operator<=(const Date& d)
{
	return !(*this > d);
}

bool Date::operator < (const Date& d)
{
	return !(*this >= d);
}

bool Date::operator >= (const Date& d)
{
	return !((*this > d) || (*this == d));
}

bool Date::operator==(const Date& d)
{
	return _year == d._year
		&& _month == d._month
		&& _day == d._day;
}
bool Date::operator>(const Date& d)
{
	if (_year > d._year)
	{
		return true;
	}
	else if (_month > d._month)
	{
		return true;
	}
	else if (_day > d._day)
	{
		return true;
	}
	return false;
}

Date Date::operator--(int)
{
	Date tmp(*this);
	tmp -= 1;
	return tmp;
}

Date& Date::operator--()
{
	return *this -= 1;
}

Date& Date::operator++()
{
	return *this += 1;
}

Date Date::operator++(int)
{
	Date tmp(*this);
	tmp += 1;
	return tmp;
}

Date Date::operator-(int day)
{
	Date tmp(*this);
	tmp -= day;
	return tmp;
}

Date& Date::operator-=(int day)
{
	if (day < 0)
	{
		return *this += (-day);
	}
	_day -= day;
	while (_day <= 0)
	{
		_day += GetMonthDay(_year, _month);
		_month--;
		if (_month == 0)
		{
			_year--;
			_month = 12;
		}
	}
	return *this;
}

 Date& Date::operator=(const Date& d)
{
	 if (this != &d)
	 {
		 _year = d._year;
		 _month = d._month;
		 _day = d._day;
	 }
	 return *this;
}

 Date& Date::operator+=(int day)
 {
	 if (day < 0)
	 {
		 return *this -= (-day);
	 }
	 _day += day;
	 while (_day > GetMonthDay(_year, _month))
	 {
		 _day -= GetMonthDay(_year, _month);
		_month++;
		if (_month == 13)
		{
			_year++;
			_month = 1;
		}
	 }
	 return *this;
 }

 Date Date::operator+(int day)
 {
	 Date tmp(*this);
	 tmp += day;
	 return tmp;
 }

Date::Date(int year, int month, int day)
{
	_year = year;
	_month = month;
	_day = day;
	if (_year < 1 || _month < 1 || _month >12 || 
		_day <1 || _day> GetMonthDay(_year, _month))
	{
		assert(false);
	}
}

Date::Date(const Date& d)
{
	_year = d._year;
	_month = d._month;
	_day = d._day;
}

int Date::GetMonthDay(int year,int month)
{
	assert(year >= 1 && month >= 1 && month <= 12);

	int monthArray[13] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30,31 };

	if (month == 2 && ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)))
		return 29;

	return monthArray[month];
}
